I am interested!

(A) is leaning in the right direction for me and it was my original choice as I read through the choices, however it does not imply Healy had anything to do with it. That is nice to know that it is more expensive but it does not say any more than that. It is you who makes the assumption that Healy knew that, and that Healy intentionally listed it for more money. Answer E states those assumptions so they are no longer just in my head, it is actually on paper and a known fact. Answer E says that he intentionally listed it and did so to increase the price.

Understand the structure of the argument. This specific one gave context, then an opinion/conclusion. Then a list of support. The answers all contradict the reasonings that they gave. B was a little iffy at first so i skipped it but I ended up eliminating all the other answers and that was all that was left. Answer choices A and E contradict reasoning number 3, C and D contradict reasoning 2. The only answer left is B.

What relevance does price have? The answer does not address the fact that people who reduced red meat intake are eating MORE fat than those who did not reduce red meat intake.

I almost got hung up on this one. I pretty quickly realized that this answer states the people consume as much fatty foods. The stimulus said that the people who reduced red meat intake consume substantially more fat. It is an assumption that i was making, but it turned out correct.

The curriculum is in desperate need of clarification. I was very lost in this lesson and swear that you just taught us this IS correct and valid, yet you are now saying it is not. I went back to clarify my understanding and found this. In the lesson titled "other formal arguments" within the "Logic of intersecting sets" tab you cover something similar. To be noted what the curriculum states is that

A→B‑m→C leads to A←s→C

Which is NOT valid.

However.

A→B

A‑m→C leads to B←s→C which IS valid.

Apparently A to C is a stretch, but B to C is not a stretch and is actually valid with the some quantifier.

Can an instructor or someone confirm this is right?

that is correct. subtle wording change, but a totally different conclusion. great point in calling out!

Interested